Catfish
Order: Siluriformes Family: Siluridae Genus & Species: Silurus glanis
The European catfish is much sought after by anglers because of its power and enormous size. It is a voracious predatory fish that lives in sluggish and stagnant freshwater habitats.
| Habitat The European catfish survives in water with a low oxygen content. It inhabits the lower reaches of the large rivers of Central and Eastern Europe, but is particularly associated with the Danube basin. It is equally at home in marshes and brackish waters.It is a highly adaptable fish and has been introduced by anglers to other parts of Europe, including Britain, and it has now colonized many muddy lakes, canals and rivers with overhanging weedy banks and tangled tree roots. |
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Behaviour
Because of its size and bulk, adult catfish usually remain solitary in order
to obtain enough food to sustain it. Young fish however, may form shoals for
protection. Catfish are most active after dusk when they hunt closer to the water's
surface. They spend the day at the bottom, in crevices or dense vegetation.
They stop feeding in winter, conserving energy by remaining inactive in deep water.
Because of its sluggish lifestyle and long lifespan, the catfish can reach huge
proportions. The largest confirmed specimen is a 3m long female, taken from the
Danube in Romania. It is preserved in the Natural History Museum in Paris.
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Feeding Young catfish eat tiny invertebrates, worms and crustaceans. As they grow, they will take the eggs and fry of other fish, upgrading to larger species such as roach and bream, as well as amphibians and small swimming mammals such as rats and water voles. Very large catfish will attack adult waterfowl, sucking them down from the surface in its immense jaws. There are also reliable reports of catfish attacking small dogs that have strayed into the water. There are also unconfirmed reports of monster catfish attacking humans. |
Breeding Catfish require a water temperature of over 18oC for spawning. The male locates a female by following her 'scent trail'. Once he has located a female, he digs a shallow depression in the lake or riverbed, using his broad mouth and belly. He ushers the female towards the nest and stimulates her into laying her eggs, which he then fertilizes. |
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| Each female can lay from 7,000 to 25,000 eggs per kg of her body weight. The male guards the eggs until after they hatch. Once the fry become free-swimming, they are left to fend for themselves. Vast nembers are eaten by fish, wildfowl and aquatic invertebrates. Surviving fry grow very fast and are sexually mature at around three to four years. They weigh around 12-18kg at nine years and can maintain this rate of growth if food supplies are sufficient. |